This invention is related to the power generation industry and, more particularly, to the field of turbine generators.
In the power generation industry, turbine generators conventionally include a stator and a rotor. The stator 10 often includes a finger plate 20 having a base 21 and a plurality of spaced-apart fingers 23, 24 connected to and extending radially inwardly, as understood by those skilled in the art, from the base 21 as shown in the prior art of FIGS. 1-2. The fingers 23, 24 of the finger plate 20 extend radially inwardly between stator coil slots 30 formed in laminations 35 of the stator 10. Conventionally, as illustrated, the stator coil slots 30 have a pair of stator coils 33, 34, e.g., one overlying the other, positioned in the slot 30. The stator coil 33 closest to the finger plate base 21 was then only supported by side walls 31, 32 of the step irons and the bottom 19 of the stator slot 30 as shown.
Problems with this prior art type of finger plate 20 have been discovered, however. As shown in FIGS. 1-2, for these types of finger plates there is no contact between the base 21 of the finger plate 20 and the bottom of the coil 33 closest to the base 21 of the finger plate 20. During use, excessive vibrations within the stator coils 33,34 can cause the deterioration of the stator coils 33, 34 and associated support structure. Also, stator slot wedges which assist in retaining the stator slot contents within the stator coil slot 30 can be desired to be used at the finger plate. The prior art finger plate 20, however, provides no support for mounting or positioning stator slot wedges within the stator coil slot 30 around the finger plate 20.
In view of the foregoing, the present invention advantageously provides a stator having a coil support finger plate which radially supports contents of a stator core coil slot. The present invention also advantageously provides a coil support finger plate for a stator and associated methods which substantially reduces the vibrations associated with conventional finger plate designs and thereby decreases stress or strain to stator coil insulation and reduces component failure. The present invention additionally advantageously provides a coil support finger plate which effectively extends the length of the stator coil slot or winding basket. The present invention further advantageously provides a finger plate for a stator which has wedge lands defined by portions of the fingers of the finger plate for mounting or positioning stator slot wedges therein so that the stator coils can then be supported by top or outer and bottom or inner portions of the finger plate as well.
More particularly, the present invention provides a stator for a power generator. The stator preferably has a plurality of laminations having a plurality of spaced-apart stator coil slots formed therein and stator coil slot contents positioned in each of the plurality of stator coil slots. The stator coil slot contents preferably include at least one stator coil. The stator also preferably has a coil support finger plate positioned at an end portion of the plurality of stator coil slots. The coil support finger plate has a base and a plurality of fingers extending outwardly from the base between the plurality of spaced-apart stator coil slots. The base includes a stator slot contents support portion positioned to underlie the stator slot contents and to support the stator coil slot contents thereon so that the stator slot contents support portion defines a stator slot bottom at the coil support finger plate.
Also, the present invention provides a coil support finger plate for a stator of a power generator. The coil support finger plate preferably includes a base and a plurality of fingers extending outwardly from the base so that at least one of the plurality of fingers also extends between end portions of a pair of stator coil slots when positioned adjacent thereto. The base preferably includes a stator slot contents support portion positioned to underlie contents of a stator coil slot and to radially support the stator coil slot contents thereon. The stator slot contents includes at least one stator coil.
Additionally, according to another aspect of the present invention, a coil support finger plate for a stator of a power generator is provided which preferably has a base and a plurality of fingers extending outwardly from the base so that at least one of the plurality of fingers also extends between end portions of a pair of stator coil slots when positioned adjacent thereto. The at least one of the plurality of fingers has a distal end portion thereof being positioned adjacent distal side peripheries of each of the end portions of the pair of stator coil slots and medial portions of the at least one of the plurality of fingers extending along only side peripheries of one of end portions of the pair of stator coil slots. Wedge lands for each of the pair of stator coil slots are formed in or defined by at least portions of the at least one of the plurality of fingers.
Further, the present invention provides a method for supporting a stator slot coil to thereby reduce vibrations within a stator. The method preferably includes radially supporting the bottom of the contents of a stator coil slot by the use of a coil support finger plate having a base portion thereof which defines a stator coil slot bottom. The method can also include positioning first and second stator coil slot wedges each to overlie a corresponding one of end portions of first and second stator coil slots and in first and second spaced-apart, wedge lands formed in the coil support finger plate. The first wedge land for the first wedge is preferably formed in a distal end portion of at least one finger of the coil support finger plate extending between end portions of the first and second stator coil slots. The second wedge land for the second wedge is preferably formed in the distal end portion of the same at least one finger of the coil support finger plate.